Simple python script to embed message image into carrier image using lsb :>

main.py

import cv2
import sys
import numpy as np

def hide(carrier_file, message_file, output_file = 'result.png', bit_plane = 0, channel = 0):
  carrier = cv2.imread(carrier_file)
  message = cv2.imread(message_file)
  output = carrier.copy()

  cw, ch, _ = carrier.shape
  mw, mh, _ = message.shape

  # clear the current bit plane with white color
  clear_mask = 2 ** bit_plane
  for i in range(cw):
    for j in range(ch):
      output[i][j][channel] |= clear_mask
      
  # embed the message
  for i in range(min(cw, mw)):
    for j in range(min(ch, mh)):
      if np.all(message[i][j] == 0):
        output[i][j][channel] ^= 2 ** bit_plane

  cv2.imwrite(output_file, output)


if __name__ == "__main__":
  carrier_file = sys.argv[1]
  message_file = sys.argv[2]
  bit_plane = int(sys.argv[3])
  channel = int(sys.argv[4])

  hide(carrier_file, message_file, bit_plane=bit_plane, channel=channel)